James m



(ModeL) t J. M. STEWART. Machine for Preparing Wood for Paper Pulp.

No. 236,856, Ratentedln. 18,1881.

ILPETHIS, ml-IYNOGRAPNER, WASHINGTON. D a

UNITED STATES PATENT OFFICE.

JAMES M. STEWART, OF TIGONDEROGA, NEW YORK.

MACHINE FOR PREPARING WOOD FOR PAPER-PULP.

SPECIFICATION forming part of Letters Patent No. 236,856, dated January18, 1881.

Application filed April 1, 1880. (ModeL) To all whom it may concern:

Be it known that I, JAMES M. STEWART, of Ticonderoga, in the county ofEssex and State of New York, have invented a new and useful Improvementin Machines for Preparing Wood for Paper-Pulp, of which thefollowin gisa specification, reference being had to the accompanying drawings, andto the letters of reference marked thereon.

Figure l is a front view of my machine. Fig. 2 is atop View of the same.

The object of this invention is to furnish an improved machine forpreparing wood for paper-pulp which shall be so constructed as toprevent the formation of splinters, and which will reduce the wood tosuch a state that it may be readily prepared for refining; also, so asto enable timber of any desired or convenient size or thickness to beoperated upon.

My invention consists in cutting or shaving off the wood from the blockby means of a series of small chisel-shaped cutters or bits fastened toor adjustable to the face of a diskshaped cutter-head, and extendingfrom some point without the center of the said cutter-head to theperiphery of the same. These chiselshaped cutters are so placed thatthey descend to the face of the cutter-head as they approach theperiphery-thatis to say, that each succeeding cutter, commencing withthe one nearest the center, is lower than the preceding one.

C is a mandrel, which revolves in bearings attached to the .top of theframe A, and to it is attached a pulley, F, to receive the drivingbeltin the usual way. Upon the forward end of the mandrel O isattached thecutter-head D. Upon the face of this cutter-head are formed, or to'itattached, several series of chisel-shaped cutters, E. These cutters E,any desired number of which may be used, descend, by a succession ofcircular steps, from the upper part of the cutter-head D (usually acone-shaped disk) to the outermost part of the same.

Instead of placing the cutters on ring-steps, as described above, aregular disk may be used and the step form produced by lengthening thecutters, one by one, as they recede from the periphery.

The cutters E are bolted either onto the face of the cutter-head or areinserted into slots and bolted from beneath.

B represents a suitable frame-work for supporting the feed-table, whichruns on the rails G, between the points H and H.

The machine being arranged as shown in the drawings, the wood, cut upinto blocks two or three feet in length, is placed across the feedtable,with one end of the block overlapping the cutters. When the block isplaced in this position the grain of the wood is perpendicular, ornearly so, to the axis of rotation of the cutter-head.

As suggested above, different styles of cutter-heads may be used, andthe cutters maybe grouped together in order and at regular intervals, asshown in the drawings, or placed irregularly. Further, the cutters areplaced at any angle, according as it may be desired to produce a shavingor a more finely-divided material.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent, is

1. In a machine for preparing wood for paper-pulp, the combination, witha cutter-head provided with a series of slots, of a series of cuttersarranged in steps, substantially as described, and for the purpose setforth.

2. The cutter-head D, composed of a series of concentric circlesdiminishing in diameter from the base outward, and provided with slotsfor the cutters, in combination with the adjustable cutters E, arrangedto form a succession of steps, substantially as described, and for thepurpose set forth.

3. The combination, with the cutter-head D, provided with a series ofslots, and adjustable cutters E, both constructed as set forth, of theframe A, shaft 0, and'rails Gr, substantially as described, and for thepurpose set forth.

JAMES M. STEWART.

Witnesses:

J. M. COOLIDGE, W. W. D. JEFFERs.

